Using Custom OS for autotuning and Semi open loop questions.

[Chris81]

Can I use my custom OS for autotuning or do I need to flash in a stock program?

I'm curious because I don't have B3605 to alter, should I use B3647 instead? How does this work?

Also, for B3647 to work correctly do I need to have the values spread out enough to take a average (wide), or should it average whatever I have? I"m asking because at the track my car won't hold the correct AFR through the shifts, just in the beginning of a shift.. I'll 13.0 at the beginning of a shift and almost 12.0 at the top of a gear when i'm not commanding it. I'm commanding between 12.8 and 13.0 from 80-100 kPa, 12.8 from 0 to 4800 and 13.0 from 5200 to 7200 all the way across.

Could there be anything I forgot to disable?

Also, what is the role of the MAF during WOT in semi open loop? Is it supposed to function or not? I was thinking it was not but i'm logging that it is.

Any help would be great!

Thanks.

[Chris81]

TTT

Anyone?

[QUICKSILVER2002]

The custom OS is designed for SD. Not sure what happens if you don't set the MAF fail frequency or disconnect the MAF.

The custom OS can be used for autotuning. Autotuning has nothing to do with the OS. It is just a feature of the scan/tuning tool. The only requirement on the OS side is that you are in SD and not running fuel trims.

B3647 should simply not be at 1.0 EQ (14.63AF) in the areas you want to autotune.

Autotune is a confusing term. It is really just a scan tool feature that lets you capture the average difference between the commanded and actual AF ratios. You then use this factor to modify the VE table in a copy/paste fashion. It is a very powerful and cool feature, but it is not automatic. You can also use it for other things besides dialing in the VE table.

The MAF has no role in SD. The values are still available in the scan tool if it is hooked up, but it has no impact how the PCM is running the car.

[caver]

AS per my other post the AFR will always fluctuate on gear changes and will vary from gear to gear.

[dfe1]

The custom OS is designed for SD

The custom OS isn't DESIGNED for SD, it's designed to enable a conversion to SD while (or whilst, depending on which side of the road you drive) retaining high and low octane spark tables. I've done both MAF and SD tunes using a custom OS with no problems. Most people would question why anyone would want to switch to a custom OS and retain the MAF sensor, but there are instances where that would make sense. As an example, with a stock or lightly modified engine, there's not much benefit from converting to SD, but if you'd like to take advantage of the Valet switch, you need a custom OS. In that case, all you'd have to do is install your existing .tun file in conjunction with an OS2 operating system, wire up the switch and you'd be done.

[Chris81]

Here is my problem though, I want to autotune the car to get the VE table in line, BUT my custom OS doesn't have B3605.. can I still use the autotune feature with my custom OS?

[GMPX]

Here is my problem though, I want to autotune the car to get the VE table in line, BUT my custom OS doesn't have B3605.. can I still use the autotune feature with my custom OS?

Chris,

Table B3605 in the V3 custom O.S's was replaced with B3647.
If you do not have a radical cam, turbo/blower then you should probably use a V2 custom O.S until you get familiar with the in's and out's of tuning. V2 will give you the Valet mode plus twin spark maps if you decide to go SD.
To get a V3 custom O.S working requires more work than a V2, transferring a factory tune over to a V2 O.S is an easy task as no major tables were changed.

Cheers,
Ross

[Chris81]

I've gotten the hang of it pretty well so far, but there is alot to learn too as always..

I've had some help in replacing some tables.. etc.. and the car runs well

So, in the autotune instructions, do I fill in B3647 with the same values as I would for B3605? Will that work?

And, for newbs like me.. is there anywhere we can take a look at the changed tables in V3 compared to V2 to see where the extra work comes from? I would really rather have B3647.

Thanks,

Chris